Tricks & Traps: Ask Dr. Bob Your Windows NT Questions

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Bob Chronister

Windows NT Magazine, June 1999

Q: How do I control synchronization between my Primary Domain Controllers (PDCs) and Backup Domain Controllers (BDCs) to minimize superfluous network activity?

I upgraded from Microsoft Windows® 95 to Microsoft Windows NT® 4.0. When I try to use previous backups to restore data, the system sends me the following error message: Foreign Tape. The tape in the drive must be erased before it can be used. Can I use the previous backups to perform a restore?

A: The format of Windows 95 and Windows NT backup tapes is completely different. Only Windows 95 computers can read Windows 95 backup tapes. If you have FAT drives, you can dual-boot between Windows NT and Windows 95, then perform a restore. If you are on a network, you can perform a restore on a Windows 95 computer, then move the data over the network. No matter which method you use to perform a restore, you need to start using the Windows NT backup application and use new tapes and save the old backups.

Q: I can't create user profiles on Windows 98 systems in my Windows NT network. The Windows 98 systems always store the profiles locally rather than on the Windows NT servers. Can I set up the Windows 98 profiles to default to my PDC’s Profiles directory?

A: The problem is that Windows 98 doesn't use the Profiles directory on a Windows NT server, only Windows NT profiles use the Profile directory. The following instructions show you how to maintain an updated copy of users' profiles on your PDC:

  1. Select Client for Microsoft Networks from the list of installed network components, and click Properties.

  2. Select Log on to Windows NT domain, enter the domain name, and click OK.

  3. Be sure that each Windows 98 user is properly set up and has an assigned home directory on a Windows NT network server.

  4. When the user logs off, Windows 98 automatically places an updated user profile in the user's assigned home directory on the Windows NT network (e.g., \\specified_server\user's home directory).

Q: I upgraded from Windows NT 3.51 to Windows NT 4.0. The upgrade process was seamless; however, the process altered some of the files on the Macintosh-accessible volume. For example, Macintosh users can no longer see filenames created on a Macintosh system that contain an underscore character, and PC users can see the filenames but can't open the files. If I replace the underscore character with a Windows NT 4.0 underscore symbol, all users can view and open the files. How do I solve this problem?

A: Upgrade to Service Pack 3 (SP3) or later and these problems will disappear.

Q: How do I prevent users from mapping network drives?

A: If you're using FAT, you can prevent mapping only through drive permissions. NTFS lets you assign permissions at the file level, so you have several options to prevent users from mapping network drives. For example, if you assign No Access to a user or group of users on \%systemroot%\system32\mprui.dll, none of the users can map a drive. If you assign No Access to \%systemroot%\system32\net1.exe, you further inhibit mapping. Finally, if you assign No Access to \%systemroot%\system32\net.exe, users can't use the Net command (i.e., users can't use a logon script to map drives).

Q: I upgraded to Service Pack 4 (SP4). When my Adaptec SCSI driver is loaded, I get a blue screen and a Stop 0x0000007B message when I boot my computer. Can I fix this problem without reloading Windows NT?

A: This problem is easy to fix whether you're running FAT or NTFS. SP4 includes two versions of the AIC78XX driver for the Adaptec 2940 and 7800 family of SCSI controllers: aic78xx.sys is 26,704 bytes, and aic78xx.001 is 56,272 bytes. To fix your problem, you need to replace the AIC78XX driver in the \%systemroot%\winnt\system32\drivers folder with the AIC78XX driver from the i386 directory in SP4.

To fix this problem on a FAT system,

  1. Boot to a DOS disk that contains both AIC78XX files.

  2. From a command prompt or Windows NT Explorer, go to the \%systemroot%\winnt\system32\drivers folder.

  3. Delete the aic78xx.sys file, and copy the aic78xx.sys file from the DOS disk into the \%systemroot%\winnt\system32\drivers folder.

  4. Remove the DOS disk, and boot into Windows NT. If you successfully boot, you've fixed the problem. If you can't boot into Windows NT, reboot to the DOS disk, go to the \%systemroot%\winnt\system32\drivers folder, delete aic78xx.sys, copy aic78xx.001 into the \%systemroot%\winnt\system32\drivers folder, and rename aic78xx.001 as aic78xx.sys.

To fix this problem on an NTFS system,

  1. Boot to a second version of Windows NT. If you don't have a second version, you can use Systems Internals' ERD Commander utility (

  2. From Explorer, check the size of aic78xx.sys in the \%systemroot%\winnt\system32\drivers folder, as Screen 1 shows.

  3. If the aic78xx.sys file in the \%systemroot%\winnt\system32\drivers folder is 26,704 bytes, copy the other aic78xx.sys file (i.e., 56,272 bytes) to the \%systemroot>\winnt\system32\drivers folder and rename it aic78xx.sys. If the 56,272-byte aic78xx.sys file is in the \%systemroot%\winnt\system32\drivers folder, copy the 26,704-byte aic78xx.sys file to the folder.


(If your browser does not support inline frames, click here to view illustration in a separate page.) Screen 1: Discovering which version of aic78xx.sys you're running

Q: What features has Microsoft added to the NTFS in Windows 2000? Will I be able to dual-boot Windows 2000 and Windows NT 3.51 or Windows NT 4.0?

A: Microsoft has added new features to the Windows 2000 file system, such as disk quotas, encrypted files, journaling, and junctions. For example, the Windows 2000 file system will automatically encrypt and decrypt files as the operating system reads them and writes them to the hard disk. In addition, the Windows 2000 file system's journaling functionality will provide a log of all changes users make to files on the volume. Reparse points will let programs trap an open operation against objects in the file system and run the program's code before returning file data. For example, Windows 2000 systems will be able to use junctions, which sit on top of reparse points, to remap an operation to a target object. This functionality is a crucial aspect of the Windows 2000 file system. Finally, administrators will be able to use quota levels, such as Off, Tracking, and Enforced, to control users' access to a drive and on a per-user basis.

To answer your second question, when you install Windows 2000, the installation upgrades any existing NTFS volumes (i.e., drives) to the Windows 2000 file system. If you're installing Windows 2000 on a system that is running any version of Windows NT other than Windows NT 4.0 with Service Pack 4 (SP4), the installation program will inform you that you will no longer be able to access earlier Windows NT versions. If you install Windows 2000 on a Windows NT 4.0 with SP4 computer, your system can use SP4's ntfs.sys to read and write to the Windows 2000 file system, but it can't use the Windows 2000 file system's new attributes. The first time you access removable media, your system will convert it to the Windows 2000 file system. In other words, this installation process limits your ability to dual-boot Windows 2000 and earlier Windows NT versions.

In addition, critics have complained about the NTFS slow performance relative to FAT. You don't have to be a rocket scientist to predict that the Windows 2000 file system will be even slower than NTFS. Thus, the never-ending upgrade spiral continues—you'll need new hardware to properly implement Windows 2000.

Q: My company used Windows 95 computers because of their easy-to-use faxing functionality. Our new computers run Windows 98, and we can't fax from these computers. Do you have any suggestions?

A: Windows 98 doesn't support fax options. However, you can install the Win95 Exchange client on your Windows 98 computers and use the Windows 95 fax options.

Q: Can I triple-boot Windows NT, DOS, Windows 95, and Windows 98 directly from the boot.ini file?

A: You can use third-party software solutions or the following Microsoft-supported method to triple-boot your system. I recommend running FAT16 on everything.

  1. Install MS-DOS®.

  2. Install Windows NT.

  3. Save bootsect.dos. This system file is usually hidden and has read-only attributes. Boot to DOS (or Windows NT), and remove the attributes at a command prompt by typing

    attrib –r –h –s

  4. At a command prompt, copy the DOS boot sector by typing

    copy c:\bootsect.dos c:\bootsect.sav

  5. Boot to DOS, and install Windows 95 or Windows 98.

  6. Repair the boot sector for the Windows NT installation. This repair creates a new bootsect.dos file for the Windows 95 or Windows 98 installation.

  7. Repeat step 4 with the Windows 95 or Windows 98 bootsect.dos file.

  8. Rename the Windows 95 or Windows 98 bootsect.dos as bootsect.w40.

  9. Rename bootsect.sav as bootsect.dos.

  10. Remove the boot.ini file's attributes.

  11. Use any text editor to modify boot.ini (I prefer the command-line program Edit). Open boot.ini, and add the following commands to the operating system section:

    c:\bootsect.dos="MS-DOS v6.22" /win95dos
    c:\bootsect.w40="Windows 95/98" /win95

The next time you boot to Windows NT, you'll have the additional choices of Windows 95, Windows 98, and MS-DOS 6.22. You must include the new switches, /win95dos and /win95, so Windows NT Startup acts as the multiple-boot process of Windows 95 and Windows 98.

Q: I installed tweak.ui on Windows 95 computers and enabled the Clear Last User at Logon feature in an effort to increase security. To my amazement, I discovered that I can easily gain access to the desktop without logging onto the domain controller. How do I fix this problem?

A: A bug in Windows 95 and Windows 98 causes this problem. You can bypass security if you enable the Require Validation by Network for Windows Access and Clear Last User at Logon policies. You can bypass the Require Validation by Network for Windows Access restriction by entering a nonexistent domain name in the Domain text box on the logon dialog box. The system will prompt you for a local logon, and you simply press Esc.

Microsoft developed a hotfix for this problem. For more information about this hotfix, go to

Q: If I dual-boot Windows NT and Windows 98, can I use the same swap space to minimize the amount of disk space used?

A: To accomplish this setup, you need to configure the Windows NT pagefile.sys and the paging file in Windows 98. The following steps walk you through the Windows NT and Windows 98 configuration:

  1. Boot into Windows NT.

  2. Click Change in the Virtual Memory dialog box on the Performance tab of the System applet in Control Panel.

  3. Select the paging file drive, and set the Initial Size (MB) and the Maximum Size (MB) to the same value.

  4. Click OK, and the system will prompt you to reboot.

  5. Reboot into Windows 98.

  6. In the Virtual Memory dialog box on the Performance tab of the System applet in Control Panel, select the Let me specify my own virtual memory settings option and enter the same minimum and maximum settings that you entered for pagefile.sys.

  7. Reboot Windows 98, and add the following section to the system.ini file:


About the Author

Bob Chronister is a contributing editor for Windows NT Magazine and president of Chronister Consultants in Mobile, Alabama. He is coauthor of Windows NT Backup and Recovery (Osborne/McGraw-Hill). You can reach him at

Send your tips and questions to Windows NT Magazine. You can also visit Bob Chronister's online Tricks & Traps at

The above article is courtesy of Windows NT Magazine.

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